直流燃弧下铜钨表界面SF₆腐蚀机理研究

With the advancement of flexible direct current (DC) transmission technology, high-voltage DC circuit breakers demand higher arc erosion resistance and arc-extinguishing gas corrosion resistance. Copper-tungsten materials are widely employed as contact materials for their exceptional comprehensive properties, and their performance directly affects the operational safety of gas-insulated circuit breaker systems. In this study, first-principles calculations were used to investigate the SF₆-induced corrosion behavior of different W/Cu surface and interface structures under DC conditions. Results show that the work function of W/Cu is structure-dependent, with the lowest value (4.28 eV) at the copper-tungsten grain boundary. SF₆ adsorbs more strongly on the W phase (adsorption energy: −1.17 eV), while the lowest adsorption energy (−5.80 eV) occurs at the copper-tungsten grain boundary; notably, anodic and cathodic environments significantly affect the adsorption and corrosion processes. After corrosion, both the work function and maximum stress of copper-tungsten decreased by 7%. This study offers theoretical support for designing high-performance copper-tungsten contact materials for high-voltage DC circuit breakers.